I installed a rear camera and monitor in my Starcraft Launch 24RLS, on the cheap....
I wasn't willing to purchase the expensive Furion wireless camera/monitor that Starcraft has as an option. Instead, I took the mount down from the outside and installed a cheap mini camera inside and sealed it up. I ran the coax line inside to the rear cabinet. I connected the power to the nearby running light wire behind dummy camera mount. I ran a small coax line to the front of the camper to provide video to my truck. I used a couple of coax connectors to allow easy connect/disconnect.
In the truck I ran a line from the hitch area to the dash. I purchased a cheap mirror monitor. It clips onto the existing rear view mirror. It looks reflective like a mirror until powered on with a camera signal.
Overall the total cost was less than $50, and the material can be found on Amazon.